OBJECTIVE: : To compare intrauterine device (IUD) use at 6 months in women randomized to receive an intrauterine copper contraceptive 1 week compared with 1 month after medical abortion.METHODS: : We recruited women undergoing medical abortion with mifepristone and misoprostol and choosing the copper IUD for contraception. We randomly assigned participants to "immediate" insertion 1 week after mifepristone or "delayed" insertion 4-6 weeks later. We followed rates of IUD insertion, 6-month utilization, expulsion, removal, and pregnancy. Participants recorded bleeding in a diary for 4 weeks.RESULTS: : We randomized 156 participants. We inserted an IUD in 97% of participants in the immediate group and 76% in the delayed group (P<.001). At 6 months, 69% of participants in the immediate group used the IUD compared with 60% in the delayed group (P=.24). Expulsion rates were comparable; 12% (8 of 69) in the immediate group compared with 11% (7 of 65) in the delayed group. Removals occurred in 14% (10 of 69) of immediate and 8% (5 of 65) of delayed group participants (P=.21). Four pregnancies occurred in delayed group participants who did not return for IUD insertion (P=.09). The immediate and delayed groups reported a median of 20 and 19 bleeding or spotting days, respectively (P=.15). We detected no cases of serious infection, uterine perforation, or hemorrhage.CONCLUSION: : Immediate insertion increased uptake of the IUD without increasing expulsions or bleeding.CLINICAL TRIAL REGISTRATION: : Clinicaltrials.gov, www.clinialtrials.gov, NCT00737178.LEVEL OF EVIDENCE: : I.